BLOOD ANALYSIS

Forensic Science Project

Activity Objectives

During this activity you should be able to:

• Describe how human blood is classified
• Identify the different blood types using the appropriate tests
• Match unknown blood types to the appropriate blood group

Procedure

Part 1 - Observing the Reactions of Known Blood Samples with Anti-Serum

• Please read the procedure and then design a table to record your observations. You will be testing four bloods (A,B,AB, and O) with two anti-serums (anti-A serum and anti-B serum). Leave enough room in your table for a drawing and description of your results.
• Gently resuspend the blood cells by inverting the sample bottle two or three times. Take a cleanspot plate and put three drops of one type of blood into two of the spots
• To one of the spots containing blood, add three drops of anti-A serum and to the other spot add three drops of anti-B serum
• Gently swirl and/or rock the spot plate for at least 30 seconds and not more than a minute to ensure the anti-serum and blood sample are well mixed. As you swirl and/or rock, carefully observe around the edges of the sample in each spot for clumping. To aid in the identification of unknown blood samples in Part II include in your table a description and a drawing of your results.
• Repeat the above procedures for the other three blood types. Record your results. Remember, it is important to ensure the spot plate is clean for each test.

Part 2 - Indentifying the Blood Types of Unknown Samples

• Choose three unknown blood type samples and repeat the procedures from Part 1 to identify the blood type in each of the unknown samples. Remember to record the number or name on each of the samples and the blood type.

Reflections on the Activity

1. What do you think was the most difficult task you were expected to perform in the lab?
2. Explain how blood collected at the scene of a crime could be used in criminal investigation.
3. Identify and describe other situations, besides criminal investigations, where a knowledge of blood types and the procedure to determine blood types might be used.

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